/Engine/Plugins/Editor/ObjectMixer/ObjectMixer/Source/ObjectMixer/Public/Views/List/ObjectMixerEditorList.h
This is the filter class used to initialize the ListModel. This filter class cannot be turned off by the end user.
const [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [UObjectMixerObjectFilter](API\Plugins\ObjectMixerEditor\ObjectFilter\UObjectMixerObjectFilter) > & GetDefaultFilterClass() const